Add Audio to Video

Drop in background music or a voiceover, sync it, and export a clean file for your editing workflow. Keep the video track as-is when possible; re-encode only when required.

Frequently asked questions

Do you upload my files?

No. Processing runs locally in your browser.

Can I replace the original audio?

Yes. This tool replaces the soundtrack with your uploaded audio.

What if the audio is shorter than the video?

Choose “Loop” to repeat, or “Trim” to keep the rest silent.

Will this reduce quality?

We keep the video track as-is when possible. If re-encoding is required, quality depends on encoder support.

Which formats are supported?

Common video inputs like MP4/WebM/MOV/MKV and audio inputs like MP3/WAV/AAC work well.

Which browsers are supported?

For best results, use the latest Chrome / Edge with WebCodecs support.